| From 91ed6fd2c383bb8f02d66e98b4a4d2f7207249dc Mon Sep 17 00:00:00 2001 |
| From: Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| Date: Fri, 3 Oct 2014 15:18:59 +1000 |
| Subject: gpu/radeon: Set flag to indicate broken 64-bit MSI |
| |
| From: Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| |
| commit 91ed6fd2c383bb8f02d66e98b4a4d2f7207249dc upstream. |
| |
| Some radeon ASICs don't support all 64 address bits of MSIs despite |
| advertising support for 64-bit MSIs in their configuration space. |
| |
| This breaks on systems such as IBM POWER7/8, where 64-bit MSIs can |
| be assigned with some of the high address bits set. |
| |
| This makes use of the newly introduced "no_64bit_msi" flag in structure |
| pci_dev to allow the MSI allocation code to fallback to 32-bit MSIs |
| on those adapters. |
| |
| Adding Alex's review tag. Patch to the driver is identical to the |
| reviewed one, I dropped the arch/powerpc hunk rewrote the subject |
| and cset comment. |
| |
| Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> |
| Reviewed-by: Alex Deucher <alexander.deucher@amd.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/gpu/drm/radeon/radeon_irq_kms.c | 10 ++++++++++ |
| 1 file changed, 10 insertions(+) |
| |
| --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c |
| +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c |
| @@ -202,6 +202,16 @@ static bool radeon_msi_ok(struct radeon_ |
| if (rdev->flags & RADEON_IS_AGP) |
| return false; |
| |
| + /* |
| + * Older chips have a HW limitation, they can only generate 40 bits |
| + * of address for "64-bit" MSIs which breaks on some platforms, notably |
| + * IBM POWER servers, so we limit them |
| + */ |
| + if (rdev->family < CHIP_BONAIRE) { |
| + dev_info(rdev->dev, "radeon: MSI limited to 32-bit\n"); |
| + rdev->pdev->no_64bit_msi = 1; |
| + } |
| + |
| /* force MSI on */ |
| if (radeon_msi == 1) |
| return true; |